Corresponding surface treatment 1) Metallized protectiv […]
Corresponding surface treatment
1) Metallized protective layer
It is necessary to prepare a conductive aqueous solution as a raw material of the plating layer, and then place the hardware in an electroplating bath containing the above solution (the portion not to be plated can be sealed with an insulating varnish), under the action of the #l-/JII electric field, A film of a material contained in the solution is deposited on the surface of the hardware, and this process is called electroplating. The film deposited on the surface of the hardware is called a plating layer. The material of the plating layer may be metal or non-metal.
Practice has shown that the electroplated layer formed on the surface of the hardware is not only beautiful and smooth, but also has a high bonding strength with the base metal under the plating layer, and the plating layer is not easy to fall off. In addition, this decorative layer is also resistant to corrosion, oxidation and long life. The price is several times to several tens of times higher than unplated hardware (related to the price of the plating material and the difficulty of the plating process).
The raw material as the plating material is made into a solution, and then the hardware to be plated is immersed in the above solution, and the raw material in the solution is deposited on the surface of the hardware to form a plating layer by using a suitable reducing agent. This method of using a chemical reaction method to obtain a coating for a hardware is called electroless plating. Compared with electroplating, electroless plating does not require power supply and electroplating equipment. It can also be plated with both metal and non-metal plating. The cost is lower than electroplating, but electroless plating forms a coating on the surface of the hardware, regardless of its corrosion resistance and oxidation resistance. The durability, durability and bonding strength with the matrix material are both worse than those of the plating.
In addition, the thickness of the electroless plating layer is generally thinner than that of electroplating, and the hardness of the plating layer is also lower than that of electroplating. This kind of electroless plating is difficult to distinguish between the electroplated layer and the electroplated layer. Only professionals can check it with special equipment. However, the simple test method on the spot is to grind the surface of the two coatings with sandpaper. Since the hardness of the electroless plating is low, the wear marks are wider and deeper than the plating layer.
2) Non-metallic protective layer
Surface oxidation treatment
The surfaces of steel and aluminum hardware are very susceptible to oxidation in air. The former will produce a layer of loose rust. This layer of rust is not only unsightly, but the air will continue to be loaded with the underlying base steel through this layer of rust until the entire steel plate becomes rust. A slightly grayish white oxide film is formed on the surface of the aluminum. Although the oxide film on the surface of the aluminum material is relatively dense, the underlying aluminum matrix can be substantially prevented from being further loaded, but the original silver-white gloss is more severely damaged. In order to prevent the occurrence of the above two phenomena, in addition to the protective decorative layer, an artificial oxide film can be artificially fabricated on the surface of the newly fabricated hardware. Surface of steel hardware
The oxide film is generally prepared in an alkali solution. After oxidation treatment, a blue-black dense Fe20 oxide film (up what is commonly referred to as baked blue) is formed on the surface, and a uniform texture of A120 and oxide film is formed on the surface of the aluminum hardware.
The artificially formed oxide film on the surface of steel and aluminum hardware is not only beautiful, flat and dense, but also has a much higher bonding strength with the substrate and is difficult to grind. This oxide film also prevents the underlying metal from further corroding by the action of air or other harmful gases. Since such an oxide film on the surface of steel and aluminum hardware has lost its original metal property to become non-metal, it is also called a non-metallic protective decorative layer.